Racket stringing machine



Jan. 12, 1937. ,1. E. DARBY RACKET STRINGING MACHINE Filed Aug. 20, 1935 3 SheetsSheet l f} ii 26/0 '5? Inventor A Home! Jan. 12, 1937. J, E DARBY 2,067,563

RACKET STRINGING MACHINE Filed Aug. 20, 1935 3 Sheets-Sheet 2 Jan. 12, 1937. J. E. DARBY RACKET STRINGING MACHINE 3 Sheets-Sheet 3 Filed Aug. 20, 1 935 Invenlor J15: Z0216 Q By Zappa/52% A Home};

i atentecl jan. 12

UNITED STATES PATENT FFIE 4 Claims.

The present invention relates to new and useful improvements in machines for restringing tennis rackets and has for one of its important objects to provide, in a manner as hereinafter set forth, an apparatus of this character embodying a novel construction and arrangement through the medium of which the original shape of the racket will be retained.

Another very important object of the inven- 19 tion is to provide a machine of the aforementioned character through the medium of which the strings may be expeditiously and uniformly tightened to the desired tension without damaging saidstrings.

15 Still another important object of the invention is to provide a tennis racket re-stringing machine embodying a construction which is such -,that after the tightening or tensioning operation I ;has been performed, it will leave both hands of the operator free to do any work desired. I

l fA still further importantobject of the inventio is to provide a tennis racket re-stringing macrime embodying novel means for controlling or {regulating the tension to which the strings are sub e ts? h Other objects of the invention are to provide ia tennis, racket re-stringing machine of the charcter described which will be comparatively sim- {ple inconstruction, strong, durablehighly efli- 530 cient and reliable in use, compact, light in weight and which may be manufactured at low cost.

An-1g: th foregoing and still further objects and advantages of the invention will become apparent from a study of the following-specificaf35 tion'ytaken in connection with the accompanying drawings wherein like characters of reference .designate corresponding parts throughout the several views, and wherein:--

Figure 1 is a top plan view of a machine constructed in accordance with the present invention.

' Figure 2 is a View partially in vertical section and partially in side elevation of the invention.

Figure 3 is a vertical sectional view through the tightening or tensioning mechanism.

j, Figure 4 is a view in vertical transverse section, taken substantially on the line 4-4 'of Figure,3l

Figure 5 is a horizontal sectional view, taken substantially on the line 5-5 of Figure 3.

Figure 6 is a vertical longitudinal sectional view, taken substantially on the line 6-6 of -.Figure 4;:

' .1 Figure? is a vertical sectional view through the adjusting mechanism, taken substantially on the line 7l of Figure 3.

Figure 8 is a detail view in horizontal section through the string gripping unit or device.

Figure 9 is a detail view in bottom plan of the string gripping unit or device.

Figure 10 is a detail view in horizontal section, taken substantially on the line !lll8 of Figure 3.

Figure 11 is a horizontal sectional View, taken substantially on the line ll-H of Figure 3. 10

Figure 12 is a detail view in vertical section, showing the means for connecting the tensioning mechanism to the foot pedal for actuation thereby.

Figure 13 is a detail view in front elevation of 15 the dial.

Referring now to the drawings in detail, it will be seen that the embodiment of the invention which has been illustrated comprises a base I from which'a tubular standard 2 rises. Fixed on anupper portion of the standard 2 is an arm 3. The reference numeral 4 designates generally a clamp which'is rotatably mounted on the upper end portion of the standard 2 above the arm 3.

As illustrated to advantage in Figures 1 and 2 of the drawings, the clamp 4 includes a frame 5 having a hub portion 6 journaled on the standard 2 and resting on the inner end of the arm 3. Pivotally mounted, at an intermediate point, on the frame 5 are vertically arranged jaws 1 which are adapted for engagement with the racket 8 in a manner to firmly secure said racket in position. Extending rotatably and slidably through the lower end portions of the jaws l are actuat- 'ing screws 9 which are threaded into the frame 5. Coil springs l0 are provided on the screws 9 and engaged with the jaws l for yieldingly urging said jaws toward inoperative position. At its lower end, the hub Bof the frame 5 is provided with a horizontal flange ll having sockets l2 in its 40 lower face. The purpose of the sockets 12 will be presently set forth.

The reference numeral l3 designates a latch for the clamp 4 in the form of a vertical rod which extends slidably through the inner end portion on the arm 3 for engagement selectively in the sockets I2. The lower end portion of the latch 13 is slidable in a guide It on the standard 2. Pivotally connected to the lower end of the latch 13 is a foot pedal l5 the inner end of which is adapted to rest on a stop 1'6 on the standard 2. Projecting from the base I is an extension I! from which a post I8 rises, said post passing through the foot pedal I5 and functioning as a guide therefor.

Mounted vertically on the outer end of the arm 3 is a substantially tubular housing I9. At its upper end, the housing I9 is enlarged, as at 20, said enlargement extending toward the clamp 4. Journaled in the enlarged upper portion 20 of the housing I9 is a toothed pulley 2|. Sliclably mounted on the upper end of the housing I9 is a gripper which is designated generally by the reference numeral 22. The gripper 22 comprises a plate 23 having a longitudinal channel 24 there: in, said plate resting slidably "on out-turned flanges 25 on the upper end "of the housing I9. Spaced guides 26 are secured on opposite sides of the plate 23, and engaged under the flanges 25 for slidably securing said plate in position, said guides 26 projecting over the channel 24 Mounted for lateral and longitudinal sliding movement in the channel 24 are co acting jaws 21 which are adapted to receive and grip the string therebetween. Referring now to Figure 8 of the drawings, it will be seen that the outer edges of the jaws 21 and the opposed vertical side walls of the channel'24 have formed therein cam pockets or notches 28 which receive rollers 9- Qi i s 3". a .tl iir d at 1 g i to the plate 23 and at their other lends to the jaws 21 for causing said jaws to move together or toward eaeh other substantially at the beginning of e tensioning o g et' ii h Jew Z e r ta ned aga qn tud na movement relative to each other through the medium of a plate (see Figure 9) which is hired t a v rs on em: i s id w s i P ate tending beneath the other of said jaws and havn a the ei i hi h a Pi n a other jaw is slidably engaged. The plate -23 is re s as at .34 t s dab g mm s e t plate 3|.

Mounted on the lower side of the plate 23 is a ed whig Passes slid b thr h a ye te me th? u per parties 9 th h s n 9- A 0, s n s is re 6 re e r s t e e 5 n is eng ed wi h the u u ned i ner en por i 4 .1 .Yiifllili y u n th P e 22 oward e rap gd or impe ative Po it v The upturned end portion 5f of the rod 35 is anchored in any suitabl m nner m he plate 2 as best seen in Figure 6 of the drawings. A stop screw 38 is threaded into the outer end of one of the j w or en a mentw th an uptu ne flange 39 (s Fi r 3 n the u er o the o n 19 v openi said a 2.1 whe gripper is returned to inoperative position by the spring 31. 1

The housing [9 is open at its lower end for the reception of a vertically movable tube 40 which is slidable on the post I 8, said tube 40 being operatively connected to the foot pedal l5 by links 41. At its upper end, the tube 49 terminates in an internal flange 42. slidably en a ed in the upper end portion of the tube 40 and rising therefrom is a rack bar 43 havingahead 44 on its lower end. A chain 45 is connected, at one end, to the upper end of the rack bar .43 and at its other end to the inner end of the gripper 22, said chain being trained over the pulley 2|. The chain 45 is operable in an opening 46. which is provided therefor in the'upper portion 20 of the housing l9. Acoil spring 41 is mounted on the rack bar 43 in the tube 4ll and has'one end engaged with the head 44 and its other end engaged'with the flange 42 for elevating said tube 40"and the foot pedal [5. The spring 41 also constitutes a resilient connectionbe'tween the" tube and the rack bar 43.

Slidably mounted on the upper portion of the tube 49 in the housing [9 and rising above said tube 49 is a sleeve 48 having mounted in its upper end portion a flange 49. The sleeve 48 is provided, at its lower end, with an extension 50 in which one end portion of a lock 5| is engaged. The lock 5! is in the form of a plate (see Figures 3 and 11) which is slidable on the post l8 and which, when swung vertically or cocked, is adapted to frictionally grip said post in a manner to arrest downward movement oi the tensioning mechanism.' The lock 5| is carried by the tube 40, said tube having "formed therein diametrically opposite openings which are so formed as to permit sufficient vertical swinging movement of said lock for same to junction.

Adjustably mounted on'the upper portion of thera c'k bar 43 is a tubular member 52 which extends slidably into the upper portion of the sleeve 48 and terminates, at its lower end, in an external flange 53 for engagement with the flange 49. Formed integrally with the upper portion of the tubular member 52 is a casing 54 which projects laterally through an opening driverticaris et 55 which is provided therefor in the housing I 9. Rotatably and slidably mounted in theoasing 54 is a shaft 5@ (see Figure 5) having fixed on its outer end portion an operating wheel 51. 'li'ixed on the inner end portion of the shaft 56' is a pinion gear 58 which is constantly in mesh with the rack bar 43. The gear 58 is ehgageable with a lug 59 in the casing 54 for positively securing the tubular member 52 in adjusted position relative t the rack bar 43. A coil spring'iifl y eld n' l urges the gear 58 toward the locking lug A pointer 6| is mounted on an outer portionof the shaft 56 for co-aotion with a dial 62' on the'outer end of the casing 54 to facilitate securingtheide sired adjustment. v Brie y, the op ra ion 9 h Fig.7.??? -9 lows:-

The racket to be refstrung is secured inposi tion on the c am 4 an said am s Totliefi 9 bring the string'to be tightened nto a igil mfifit with the ipp r T e gtfi i 1S inserted tween the jaws 21 and the operator then pr 'ses downwardly on the foot pedal I5. Whe is done the latch I3 is elevated and engages none of the sockets l2 tor looking the clamp! against r ta io iwar n ee 'bnthe b fi ai l5 also moves the gripper 22 away fro the racket 8 on the clamp "a m nners te string. As the gripper 2'2'mo'ves" away from the racket tthe' spring "3] is compressed, the stop screw 38, which is mountedin one of the" jaws 21,15 moved 'o'ut'of engagement with the flange 39 .and the'comp'ara veiy weak springs 30' are thus permittedtomove Said jaws 21 toward each other into engagement'withthe string. Then, the'g'reater'the tensionthatis ext on the r n i l s 'el te w lbe thgf ip- "spring'4'! being compressed between the head 44 Thesleeve 48 'also moves and the flan'g'e'42. downwardly'with the tube 4.0 untilFthe flange 49 engages the flange 53,,thus retarding said sleeve 48 relative to the tube and causing'itheilock v Q0 ping action of the'jaws 2'! by reason of the rollers .5] to grip the stationary post l8 ina'manne't t0z prevent further downward movement of said tube 40. By pulling the shaft 56 outwardly against the tension of the spring in a manner to disengage the gear 58 from the lug 59 the tubular member 52 may be raised or lowered on the rack bar 43, thus increasing or decreasing the distance between the flanges 49 and 53 for causing the lock 5| to function at any desired predetermined point. When the shaft 56 is released the spring 60 again engages the gear 58 with the lug 59 for locking the tubular member 52 and the rack bar 43 together. When the operation has been completed the several springs return the tensioning mechanism to retracted or inoperative position and the latch i3 drops by gravity in inoperative position.

It is believed that the many advantages of a racket stringing machine constructed in accordance with the present invention will be readily understood, and although a preferred embodiment of the device is as illustrated and described, it is to be understood that changes in the details of construction and in the combination and arrangement of parts may be resorted to which will fall within the scope of the invention as claimed.

What is claimed is:--

1. A racket stringing machine comprising a supporting structure, a clamp for a racket rotatably mounted on said supporting structure, a string gripper operatively mounted on the supporting structure, and common means for actuating said gripper and for releasably locking the clamp against rotation.

2. A racket stringing machine comprising a supporting structure, a clamp for a racket rotatably mounted on said supporting structure, a string gripper slidably mounted on the supporting structure, a lever, means operatively conneot ing the lever to the gripper for actuating said gripper, adjustable means for limiting the movement of the lever, and means operable by said lever for releasably securing the clamp against rotation on the supporting structure.

3. A racket stringing machine comprising a supporting structure, means for mounting a racket on said supporting structure, a gripper operatively mounted on the supporting structure and adapted to tension the strings of a racket, a manually operable lever mounted on the supporting structure, a yieldable connecting means operatively connecting the gripper to the lever, and adjustable means for arresting said connecting means after a predetermined movement of the gripper.

4. A racket stringing machine comprising a standard, a clamp for a racket rotatably mounted on said standard, an arm mounted on the standard, a gripper slidably mounted on the arm and engageable with a string from the racket for tensioning said string, a post mounted on the supporting structure, a lever, a latch connected to said lever .and engageable with the clamp for releasably securing said clamp against rotation, a tube slidable on the post and connected to the lever for actuation thereby, a resilient connection coupling the gripper to the tube for actuation thereby, and adjustable means for locking the tube to the post against actuation by the lever after predetermined movement of said tube in one direction.

JOHN E. DARBY. 

